Electrical signal translating apparatus



June} 1, 1940.

E. c. GUEDON 2,2Q3,820

ELECTRICAL SIGNAL TRANSLATING APPARATUS Filed April 30, 1938 mug . 3nventor Emile C. Guedon Patented June 11, 1940 UNITED. STATES ELECTRICAL SIGNAL TRAN SLATING APPARATUS Emile C. Guedon, Audubon, .N. J., assignorto Radio Corporation of America, a corporation of Delaware ApplicationApril 30, 1938, Serial No. 205,233

, This invention relates to electrical signal translating apparatus, and more particularly to a pick-up device for reproducing sound from a of mechanical vibrations other than those impartedto the reproducing needle by the record,

and this is especially true in the case of inexpensive machines. One common source of such vibrations, for example, is the drivingmotor of the phonograph from which mechanical vibrations are transmitted to the sound translating apparatus and are reproduced thereby as undesired noises. The order of magnitude of such disturbances is usually such that they do not cause appreciable distortion of the sound reproduced from the record, but when reproduction of a record has been completed and the record is being changed while the motor is operating, these disturbances sometimes become quite evident and often fairly annoying.

The primary object of my present invention is to provide improved electrical sound translating apparatus which will be free from the aforementioned objectionable feature.

More particularly, it is an object of my invention to provide improved electrical sound translating apparatus which can easily and automatically be so conditioned during changing of records that no sounds or noises will be reproduced thereby at this time.

Another object of my invention is to provide an improved electrical pick-up device which is adapted to cooperate with a needle gauge of the type disclosed in my copending application,

Serial No. 187,935, to be automatically rendered inoperative to reproduce sound when associated with such needle gauge.

Still another object of my invention is to provide improved sound translating apparatus as aforesaid which is simple in construction, inexpensive in cost, easy to manufacture, and highly efiicient in use.

In my above-identified copending application,

loading type to suitable gauge the needle in the, needle socket of the pick-up. According to my present invention, I provide the pick-up with a short-circuiting switch connected across its output terminals and arrange it to coact with a projection on the support when the pick-up is (Cl. nil-400.4)

placed thereon, the said projection serving to automatically close the short-oircuiting switch wherebymechanical vibrations originating in the phonograph motor or other sources are prevented from being transmitted through the pick-up to the amplifier and loudspeaker mechanism of the phonograph. l

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description of one embodiment thereof, when read in connection with the accompanying drawing, in which Figure 1 is an elevational view showing a pickup device constructed: according to my invention in cooperative relation with its support, Figure 2 is an enlarged, plan view of a pick-up according to my invention, and

Figure 3 is an elevationthereof.

Referring more particularly to the drawing,

wherein similar reference characters designate corresponding parts throughout, there is shown, in Fig. l, a motor board I having an opening 3 therein into which is fitted a combined pick-up supporting and needle gauging device of the type disclosed and claimed in my above identified coedge of a substantially rigid, unitary pick-up arm 2| in the free end of which the pick-up I3 is mounted.

The pick-up device l3 may be of any suitable type and is provided with output terminals 23 and 25 for external connection to suitable amplifying and loudspeaker apparatus (not shown). A switch constituted by a pair of spring blades 21 and 29, the former of which is connected to the output terminal 23 and the latter to the output terminal 25, serves, when closed, to short circuit the pick-up device l3, since this switch is connected in shunt relation thereto. The spring blade 29 is somewhat shorter than the blade 21 and is provided with a downward extension 3| adapted to be engaged by the spring blade 27 when the latter is moved upwardly a sufiicient distance. The blade 21 is also provided with a downward extension 33 which is adapted to be engaged by a projection 35 on the supporting post I! when the arm 2| and its pick-up I3 are placed upon the supporting posts I5 and IT. The

. projection or extension 35 is so arranged on the post I! that, when a predetermined edge of the pick-up arm 2| rests in the notch IS, the spring blade 21 of the switch will have been moved up thereby into contact with the downward extension 3| of the spring blade 29.

The pick-up arm 2l-is mounted .for pivotal movement relative to a record supporting turntable (not shown) and also relative to the supporting posts l5 and H, the posts l5-'-l1 being fixedly mounted on the motor board I to one side of the turntable. From the foregoing description it will be apparent that, by merely resting the pick-up arm 2l on the supports 15 and I! in the predetermined relation previously described, the projection 35 will automatically close the switch 21-29 and thereby short circuit the pick-up device l3. Thus, the transmission to the sound reproducing apparatus of vibrations originating in the phonograph motor, the turntable, or any other parts of the apparatus will be entirely avoided while the pick-up arm 2| is in its rest position on the supporting posts l5 and I1.

Although I have shown and described but one embodiment of my invention, it will be apparent to those skilled in the art that many other modifications thereof are possible. I therefore desire that my invention shall not be limited except insofar as is, made necessary by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. In combination, a pick-up arm, an electrical signal translating device carried thereby, a normally open switch carried by said device and connected in shunt therewith, said switch being adapted, when closed, to render said device inoperative to translate signals, a support for said arm and said device, and means on said support adapted to close said switch when said device is placed on said support in predetermined relation thereto.

2. In combination, a pick-up arm, an electrical signal translating device carried thereby, a normally open switch carried by said device and connected in shunt therewith, said switch being adapted, when closed, to render said device inoperative to translate signals, a support for said arm and said device, and a projection carried by said support, said projection being adapted to close said switch when said device is placed on said support in predetermined relation thereto.

3. The invention set forth in claim 2 characterized by the addition of a record supporting member, and characterized further in that said support is fixedly mounted-to one side of said member.

' 4. The invention set forth in claim 2 characterized by the addition of a record supporting member, characterized further in that said pick-up arm is constituted by a substantially rigid member mounted for pivotal movement relative to both said support and said record supporting member, characterized further in that said signal translating device is carried by the free end of said arm, and characterized still further in that said support is fixedly mounted to one side of said record supporting member.

EMILE C. GUEDON. 

